[mythtv-users] playback not smooth regardless of source

Seth Daniel mythtv.org at sethdaniel.org
Tue Feb 27 14:56:20 UTC 2007

On Tue, Feb 27, 2007 at 10:11:13AM +0000, Mark Kendall wrote:
> On 2/27/07, Seth Daniel <mythtv.org at sethdaniel.org> wrote:
> >
> > Alright.  I hope I have understood you correctly.  The file was fairly
> > big, too big to send to a mailing list anyway.  I have placed it here:
> >
> > http://sethd.org/myth/frontend.log
> Ok - everything looks fine.


> A couple of observations:-
>  - as mentioned before (by someone else), you'll almost certainly be
> better off using opengl vsync (frontend setting). Using this, video
> timing won't be impacted as much by cpu load/other processess and
> refreshes will be in sync with the monitor.

I think I mentioned this.  I've had it both on and off and I don't see
any difference in playback.

> - your current setup is taking a standard def, interlaced source and
> deinterlacing it. It is then displaying it using a higher definition,
> interlaced display mode.
> The second point is probably your problem.  I would try one of two options:-
>  - if possible, try displaying at 480i (i.e. normal, interlaced
> standard def) using opengl vsync and no deinterlacer. I'm assuming
> you're using dvi and that your monitor/tv can support it.

Yes I'm using DVI.  

Isn't one of the advantages of using something like MythTV the ability
to 'upscale' video?  When I watch a DVD on my Zenith DVD player it can
upscale to 1080i.  People on this list have talked about upscaling *all*
of their video.  To put it mildly it would be extraordinarily
disappointing if I could only watch DVDs at 480p or SD at 480i.  I will
wonder why I even bothered to build a myth box when I could have just
bought a DVR.

>  - otherwise, I'd go for 720p using bobdeint and openglvsync.
> If you can get the first one working, that should give you a yardstick
> for what 'good' quality looks like. What you want to aim for is
> matching as closely as possible the characteristics of your video
> source with the characteristics of how it's being displayed.

I've run at 720p and 1080i and I get the same problem regardless of

> Along the same lines, with your HDHomerun, the tv is expecting 1080i
> and you're giving it deinterlaced 1080i. So try turning off any
> deinterlacing (and turn on opengl vsync) and see how that looks.

I've tried turning off deinterlacing.  Problems with playback still
occurred with HD.

> If either of those options still looks bad, send over some more
> logs... (and maybe your xorg.conf and xorg logs)

I'll happily send over more logs.

seth / @sethdaniel.org
Immortality...a fate worse than death.

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